Previously, theme hbr files were compiled to an IIFE, which would be executed before the app is booted. That is causing silenced deprecations to be printed, because the deprecation-workflow isn't set up when the IIFE is run.
This commit updates the theme compiler so that it matches the ember-cli-based raw-hbs compiler. Templates are output to normal modules, which will then be loaded by the existing `eager-load-raw-templates` initializer. This runs after the app has started booting.